The present invention relates to a device for transmitting and/or receiving signals in a wireless communication system and a method for controlling a selection of antennas in a wireless communication system.
The term “selection of antennas” as used in the present specification comprises the selection of antennas or antenna elements from a number of antennas or antenna elements in order to form or create a suitable antenna beam from the selected antennas or antenna elements, as well as the combination of some or all of the number of available antenna elements or antennas in order to form a suitable combined antenna beam.
Generally, antenna beams can be created in a transmitting and/or in a receiving device. They are typically created by selecting a suitable one out of a number of fixed beam antenna elements or antennas or by a combination of selected ones of the fixed beam antenna elements or antennas. A fixed beam antenna or antenna element can hereby be any kind of antenna or antenna element which has at least a temporarily fixed beam, e.g. a beam which is always pointing in the same (main) direction or a beam which is variable in relation to its direction but can be fix for a certain period of time.
Typically, the beam forming of antennas is used in radio communication systems in order to increase the signal-to-noise ratio (SNR). In case that interference between simultaneously or in parallel transmitted data streams or signals is present, antenna beam forming is used to increase the signal-to-interference-plus-noise ratio (SINR) by increasing the wanted signal power and/or decreasing the power of unwanted interference. In case of receiving devices which have more than one receiving chain, e.g. for a diversity reception, the reception of Multiple Input, Multiple Output (MIMO) transmissions and the like, it is important that the signals received by the different receiving chains are as uncorrelated as possible in order to optimize the performance.